L'il help identifying parasitic drain on battery?

[WeeJock]

Hi all,

Inherited my girlfriend's 1.4 Corsa-b (Holden Barina, actually.... down in Oz with the convicts ATM) and - after getting it roadworthy - have started to have a bit of fun with it; alloys on, Spax shocks on the way, etc, etc.

Now I also inherited a fairly new battery and mysterious, whispered warnings......
"Stay off the moors"
"won't start if left alone for a few days.... or overnight if only run to the station and back"

The former I put down to a my girlfriend being a bit on the odd side. But, for the latter - and in order not to cuff this new battery - I started investigating the electrics. Forgive my verbosity, but it might be useful to anyone else diagnosing a similar problem.

Fairly sure I've identified it as a parasitic drain and *not* an alternator issue (Phew);

* Engine off. Voltage across the battery, 12V

* Engine running. Voltage across battery 13 - 14V; I forget exact figures, but looked healthy

* Doors closed, everything off again, I was drawing 0.47Amps from the battery. Once the Triple display fades out - you need to set the time first - it drops to 0.2 Amps

* Thought I'd check the rectifier (internal to the alternator), in case a short or low resistance in there. Unbolted the electrical connections of the alternator, no change - 0.2 Amps still being drawn.

* By a process of fuse removal, trusty Haynes manual at my side, I identified that one (or more) of the circuits attatched to Fuse1 were to blame; "Direction indicators, diagnostic connector, interior lights, horn, triple info display, radio". Popping the fuse out dropped the current draw to zero

* disconnecting the radio's own fuse, current drops to 0.27 Amps, down to 0.01 Amps when the display fades out.

* then unplugging the triple display, current drops to 0.01 Amps and stays there.

My question's this: what sort of drain do other Corsa owners experience?
Does the 0.2 Amps drawn for the radio seem excessive to you folks?
What about 0.26 Amps for the triple display when it's on (I can't be sure it's always fading out)

Or does this all seem normal? Maybe I've got an intermittent short to track down and my parasitic drain theory is way off?

Any info on your own figures / experience would be appreciated.

Thanks in advance!

[richardhhha]

i would say that 0.2amp draw is not enough to drain a battery over night, unless the cells in the battery are dischargine over the night, what you need to do mate it take it to a grrage and get them to do a battery test then can tell you wether the battery is any good or just knackered,

ive seen batterys sold one day and the cars on the back of a flat bed the next as the battery was fudged!

[Adam-D]

unplug the mfd

ive seen that drain it before now

[WeeJock]

Transpired over time to be weather dependent; the drain must have been rising above the 0.2Amps in wet - or dewy - conditions and flattening the battery. I was only measuring it on nice Saturday mornings, of course.

Believe it or not, the RADIO was ultimately to blame (though I'll be keeping an eye on my earthing in the coming months)! Ditched the old radio and everything is now A-OK.